[SkyDancer]

Same thing he did/they did in class but then reheated and placed in cow hide shavings to cool.

[MtnClimber]

The red hot and quick cooling forms very small crystal structure in steel. Small structure is hard, but brittle. Long crystals from slow cooling bends easily and is soft. The ideal knife blade is in the middle, moderately hard, but not too brittle.

The heating to below red hot and then slow cooling is called the tempering process and lets some of the crystalline structure grow so it is less brittle. The Case brand knives have a logo Case XX. The old Case knife blades were tempered twice. Each tempering was recorded by scratching an X on a part of the blade that would not be seen.